Rolling-mill drive



Nov. 4, 1924. 1,514,17

J. W. SHEPERDSON ROLLING MILL DRIVE Filed 001. 2. 1919 2 Sheets-Sheet 1 Nov. 4 1924. 1,514,178

J. W. SHEPERDSON ROLLING MILL DRIVE Filed Oct. 3, 1919 2 Sheets-Sheet 2 Patented Nov. 4, i924. I

' lfi-lddild seas.

JOHN W. SHEPERDSO'N, OF WORCESTER,

CONSTRUCTION COMPANY, OF WORCESTER,

MASSACHUSETTS.

Application filed October 2,

To all wkome't may concern:

Be it known that I, JOHN W. SHEPERD- SON, a subject of the Kingdom of Great Britain, residing at Worcester, in the county of Worcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in a Rolling-Mill Drive, of which the following, together with the accom anying drawings, is a specification.

y invention relates to rolling mill drives and has particular reference to the adaptation of electrical apparatus for driving the several trains of rolls of a continuous mill.

The object of my invention is to provide a novel arrangement of electrical apparatus in connection with the rolls, whereby reliability in the continuous operation of the mill, as a whole, is increased, and whereby the speed of operation of the difi'erent trains of rolls may be readily controlled in order to vary both the form of product and the rate of production of the mill.

In the operation of rolling mills it is well known that while the. rolls of the several passes must be driven at difierent speeds, nevertheless it is most essential that t e ratio between the speeds of the individual rolls must remain the same while material of a given form and cross section is beingpassed through the rolls. It is also well known that when it is desired to roll stock into difi'erent forms and cross sections, provision must be made whereby either the speed of the mill as a whole may be adjusted or the speed of the individual rolls may be adjusted to obtain an entirely new speed relation between the trains. In the latter case it is esential that the new speed ratios must be maintained during operation of the mill, as before.

By m invetnion I propose to obtain all of the above described advantageous results in a continuous mill Toy-driving all of the rolls from an ad'ustable speed electric motor, and so distri uting the power of the motor to the rolls that individual speed adjustment of certain of the rolls may beobtained, where desired, without disturbing the operation of the mill as a whole.

lin the accompanying drawings, Figure 1 is a diagrammatic view of'the rolls of a MASSACHUSETTS, ASSIGNOR MORGAN MASSACHUSETTS, CORPORATION OF ROLLING-MILL DRIVE.

1919. Serial No. 328,059.

mill with electrical apparatus connected thereto in accordance with my invention.

Figure 2 is a modification in the arrangement of the apparatus shown in Fig. 1.

Similar reference characters refer to similar parts in the different figures.

, Referring to Fig. 1, a main motor 1. shown as of the induction type, is'connected to supply mains 2 that are energized from a suitable alternating current source, such as a poly-phase generator 3. The shaft 4 of the motor 1 is adapted to drive a series of roughing rolls 5 through reduction gearing 6, and a.series of bevel gears 7 arranged on a countershaft 8. The motor 1 is also adapted to drive a series of intermediate rolls 9 through bevel gearing 10 carried on the motor shaft 4. The exact arrangement of the rolls and of the gearing forms no part of the present invention, and is only shown diagrammaticall it being understood that any other suitab e arrangement of rolls may be employed.

A direct current. generator 11 is also connected to the shaft 4 of the motor 1 and is adapted to energize supply means 12. A plurality of roll motors 13 are respectively connected to the supply mains 12 and are adapted to drive a series of finishing rolls 1% through suitable pinions 15. The motors 13 are preferably of the constant speed type and are respectively provided with a field winding 16, one terminal of which is con nected to one bus-bar 17 of a constant po tential field energizing circuit, and the other terminal of which is connected to the other bus-bar 18 through an adjustable field rheostat 19. The field winding 20 of the generator 11 is also connected across the bus bars 17 and 18 through an adjustablefield rheostate 21. Thebus-bars 17 and 18 are connected to the terminals of a direct current .exciter 22 that is direct connected to an al-' ternating current motor 23 supplied from the mains 2. 7

The speed of the motor 1 is adapted to be adjusted by means of a suitable speed regulating set, which is here shown as comprising a poly-phase commutator motor 24 connected to the rotor of the main motor 1 through slip rings 25, and mounted on the same shaft with an asynchronous generator s'et. roughing tram at 26 connected to the supply mams 2. The greater the amount of electrical energy absorbed by the motor 24, the lower will be the speed of the motor 1, and in order to properly regulate the amount of energy transformed by the regulating set, a transformer 27 having adjustable taps 28 is provided. It is to be understood that other suitable means may be employed in order to adjust the speed of the motor 1.

Having described the arrangement of apparatus entering into my invention the operation thereof is as follows :-When the rolls 5 and 9 are driven directly by the motor 1, the finishing rolls 14 are simultaneously driven by the motors 13 at speeds havinga fixed relation to the speeds of the,

.other rolls, owing to the fact that the direceive their fieldexcitation from a source of constant voltage.

rect current motors 13 When it is desired to change the speed of the mill, as, a whole, without changing the speed ratios between the trains or the 1ndividual rolls, the speed of the motor is adjusted by means of its speed regulating The motor 1 thereupon drives the an increased or decreased speed. As the speed of the generator 20 changes, the voltage impressed across the supply mains 12, and consequently the speeds of the motors 13 change in the same proportion. Changes in the speed ratio between the various finishing rolls 14 or between the finishingtrain and the other trains, are accomplished by adjustment of the field rheostats 19 of the individual roll motors 13 or of the field rheostat 21 of the generator 11.

Referring now to Fig. 2 the arrangement of the main motor 1 and of the finishing roll motors 13 is the same as shown in Fig. 1. Direct current motors 27 and 28 are provided to drive the trains of rolls 5 and 9 throughgearing 6, 7, and 10, in the same manner as shown in Fig. 1. The motor 27 is provided with a field winding 29 and a field rheostat 30, and the motor 28 is provided with a field winding 31 and a field rheostat 32, all connected between the busbars 17 and 18. With this arrangement of apparatus, the general scheme of operation is the same as described with respect to Fig. 1, with the exception that additional adjustments of the speeds of the roughing and intermediate trains are obtainable.

A consideration of the above described modes of operation shows thatthe mill is capable of adjustment in a number of different ways, without changing the arrangement of apparatus, which may. be briefly stated as follows :-(1) The speed of the mill, as a whole, may be changed by adjustment of the speed of the main motor 1.- The speeds of all of the motors may be changed, independently of the main motor,

by adjustment of the voltage of the generacombinipg two or more single adjustments.

For example, a change in the speed of the mill, as a whole, may be obtained by combining (1)and (2) in .order to secure a mill speed not obtainable by the use of either (1) or (2) alone. Thus, the speed of the main motor 1 might be increased twentyfive per cent at the same time the voltage of thegenerator 11 is lowered ten per cent;

the resulting mill speed being determined by the cdmbined effect of the two changes with respect to the operatingv characteristics of the electrical apparatus.

' From the foregoing it is apparent that a continuous mill equipped with apparatus farranged'in accordance with my invention is adapted for the production of a wide range of forms, thus securing a flexibility and freedom of operation not heretofore obtained in continuous mills in which the speed relation between different rolls and trains is permanently fixed.

While have shown-my invention'as applied to a particulararrangement of rolls, it is obvious that the same arrangement of electrical apparatus can also be applied to other.mills of the same general t pe with- ,out departing from the spirit an scope of my invention. I desire therefore that only such limitations be placed thereon as come within the scope of the appended claims.

I claim,

1. In a rollingmill drive, the combination with a plurality of rolls arranged in sepa-- 2. In a rolling mill drive, the combination with a plurality of rolls arranged inseparate trains, and a single source of electrical energy, of an electric motor connected to said source and adapted to provide power for driving said rolls with a predetermined speed relation between the trains, and means for independently varying the speed relation between'certain of the trains and between certain of the individual rolls.-

3. In a rolling mill drive, the combination I with a plurality of rolls, a source of altermotor connected to said source, of a generator driven bysaid moto'rfor supplying electrL cal energyto constant speed motors driving said rolls, whereby the speeds of said roll motors vary directly with the speed of the main motor, and means. for independently controlling the speed of each of said roll motors. 7 4. In a rolling mill drive, the combination with a plurality of rolls, a source of alternating current, an adjustable speed motor connected to said source, and a direct current generator driven by said motor for supplying energy to shunt wound motors driving said rolls with a predetermined speed relation therebetween, of an independent source of direct current for providing the entire field excitation to'said generator and to said roll motors. Y v

5.111 a rolling mill drive, the combination with a plurality of'rolls', asource of alternating current, an adjustable speed motor connected to said source, and a direct current generator driven vby-said -motor for supplying energy toconstant speed motors driving said rolls with a predetermined speed relation therebetween, of means for providing the entire field excitation-for said 4 generator and said roll motors at constant motor driving the rolls of v ing-roll stands, a plurality of motors correvoltage, and further means for independently controlling the operation of each of said roll motors.

6. A hot mill for rolling metal including a plurality of roughing-roll stands and aphirality of finishing-roll stands, a common motor driving the rollsof the several roughing roll stands, a plurality'of motors corresponding in number with the finishingroll stands and connected operativelyfone to each of said finishing-roll stands, and a common .source of power for all of said motors.

7. Ahot mill forrollin metal including a plurality of roughing-r0 stands and a plurality of finishing-roll stands, a common a the several roughsponding'in number with the finishing-roll stands and connected operatively, one to each ofsaid finishing-roll stands, and means I for operating all of said motors from a common source of power, the fluctuations of which afiect all of the driven units equally.

Dated this 20th day of .September,-1919.

' JOHN W. SHEPERDSON,

Witnesses:

.NELLm WHALEN, Pmtnmrn COMBERBACH. 

